Chandrayaan-1:
Chandrayaan-1, meaning “Moon Craft” in Sanskrit, was India’s first deep-space exploration mission. Launched by the Indian Space Research Organisation (ISRO) on October 22, 2008, it marked a historic milestone in India’s space program. The spacecraft was successfully placed into a lunar polar orbit at an altitude of 100 km to study the Moon’s surface and its environment.
Launch and Journey
The mission was launched from the Satish Dhawan Space Centre in Sriharikota using the Polar Satellite Launch Vehicle (PSLV). Specifically, the PSLV-C11 variant was used. The PSLV was specially modified with larger strap-on motors for this mission to carry the heavy spacecraft beyond Earth’s gravitational pull and into the lunar trajectory.
Primary Objectives
The Chandrayaan-1 mission was designed to achieve several critical scientific goals over its planned two-year lifespan:
Topographical Mapping: To create a high-resolution, three-dimensional map of the entire lunar surface.
Mineralogical Mapping: To study the distribution of various minerals and chemical elements on the Moon, such as magnesium, aluminum, silicon, calcium, iron, and titanium.
Search for Water: To look for evidence of water ice, particularly in the permanently shadowed regions of the lunar poles.
Scientific Payloads (Instruments)
S.No. | Name of the Scientific Payload | Origin |
1 | Terrain Mapping Camera (TMC) | India |
2 | Hyper Spectral Imager (HySI) | India |
3 | Lunar Laser Ranging Instrument (LLRI) | India |
4 | High Energy X-ray Spectrometer (HEX) | India |
5 | Moon Impact Probe (MIP) | India |
6 | Chandrayaan-1 X-ray Spectrometer (CIXS) | Abroad |
7 | Near Infrared Spectrometer (SIR-2) | Abroad |
8 | Sub keV Atom Reflecting Analyzer (SARA) | Abroad |
9 | Miniature Synthetic Aperture Radar (Mini SAR) | Abroad |
10 | Moon Mineralogy Mapper (M3) | Abroad |
11 | Radiation Dose Monitor (RADOM) | Abroad |
Two of the most notable instruments included:
- Moon Impact Probe (MIP): An Indian payload designed to separate from the main spacecraft and intentionally crash-land near the lunar South Pole. During its descent, it analysed the thin lunar atmosphere and captured close-up images. It also famously placed the Indian tricolor flag on the lunar surface.
- Moon Mineralogy Mapper (M3): A NASA-provided imaging spectrometer that played a vital role in identifying the chemical signature of water and hydroxyl molecules on the Moon.
Major Discoveries and Scientific Achievements
Chandrayaan-1 was a highly successful mission that fundamentally changed the global understanding of the Moon.
- Discovery of Lunar Water: The most significant achievement of the mission was the clear, undisputed discovery of water (H₂O) and hydroxyl (OH) molecules on the lunar surface. This was confirmed by the M3 instrument and supported by data from India’s MIP.
- Lunar Magma Ocean Hypothesis: The data collected by the mission provided strong evidence that the Moon was once completely molten, supporting the scientific theory known as the “Lunar Magma Ocean.”
- Ice in Polar Craters: Radar instruments on the spacecraft detected signals indicating the presence of thick water ice layers hidden in the dark, extremely cold craters at the lunar north pole.
Conclusion of the Mission
The mission was initially planned to operate for two years. However, after functioning for 312 days and completing more than 3,400 orbits around the Moon, the spacecraft lost communication with Earth on August 29, 2009. Despite this early conclusion, Chandrayaan-1 successfully achieved over 95% of its planned scientific objectives. It laid a strong technological and scientific foundation for ISRO’s subsequent lunar missions, Chandrayaan-2 and Chandrayaan-3.
